Unwielding a weapon branded with distortion or casting Excruciating Wounds on it causes severe translocation miscast effects, including up to 43 damage or even banishment to the Abyss (25% chance). This is a very good reason to avoid wield-IDing random magic and artifact weapons -- while distortion is a very rare brand, wielding it on accident can easily result in the end of a promising run. Note that followers of Lugonu are protected from this effect.

Strategy

Since the brand's effect is not dependent on the damage your weapon does, it works best on a fast weapon with low base delay. But remember that the nature of the brand prolongs fights by blinking enemies away from you, disperses enemies over the whole floor, and ultimately banishes many stronger foes for decreased experience gains. If you have multiple weapons you intend to switch between and don't plan on following Lugonu, you almost certainly don't want to deal with a distortion weapon's guaranteed miscast effects.

Pious followers of Lugonu can have a weapon branded with distortion once per game, guaranteeing them access to the brand's effects. Having a distortion weapon on hand can be useful for when you want to keep monsters at bay while dealing irresistible damage. It can even banish creatures that are immune to magical effects like the Hell lords -- just be aware that particularly powerful banished creatures are likely to be waiting for you should you travel to the Abyss yourself.

Be careful about the blinking effect. It gives you no message when it occurs, suddenly leaving you with empty space where that monster used to be. If you're attacking by attempting to move into the monster, your next swing will move you instead, and that can be bad when you move out of a choke-point or into unfavorable terrain. Attacking using Tab lets you avoid this, but you may still move unintentionally if other monsters are within your line of sight.

When facing another creature wielding a weapon of distortion (or one with a naturally distortion-branded attack, like spatial vortices), do your best not to let them into melee range if you can at all help it.

Unwielding a distortion weapon can serve as a last resort to teleport you while confused, but be aware that the consequences of this can be lethal.

It can also serve as a way to send yourself to the Abyss without having an entrance handy, which may be useful in particularly dangerous endgame locations like the Tomb or a Ziggurat. Just be aware that you'll return to the exact place you left (if you survive your jaunt to the Abyss at all).

History

Prior to 0.19, distortion weapons could sometimes heal blink frogs (including the unique blink frog Prince Ribbit), who were immune to all of the effects of the distortion brand. Additionally, the spell Warp Weapon existed, which could apply a temporary distortion brand to your weapon.